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<TITLE>Scheme 48 Manual -- Cells</TITLE>

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<EM>Scheme 48 Manual</EM> | <A HREF="s48manual.html#top_node">Contents</A> | In Chapter: <A HREF="s48manual_35.html">Libraries</A><BR>Previous: <A HREF="s48manual_41.html">Sparse vectors</A> | Next: <A HREF="s48manual_43.html">Queues</A>
<H2>Cells</H2>

<P>These hold a single value and are useful when a simple indirection is
 required.
The system uses these to hold the values of lexical variables that
 may be <CODE>set!</CODE>.
<P><UL><LI><CODE>(cell?<I>&nbsp;value</I>)&nbsp;-&gt;&nbsp;<I>boolean</I></CODE><A NAME="1">&nbsp;</A>
<LI><CODE>(make-cell<I>&nbsp;value</I>)&nbsp;-&gt;&nbsp;<I>cell</I></CODE><A NAME="2">&nbsp;</A>
<LI><CODE>(cell-ref<I>&nbsp;cell</I>)&nbsp;-&gt;&nbsp;<I>value</I></CODE><A NAME="3">&nbsp;</A>
<LI><CODE>(cell-set!<I>&nbsp;cell&nbsp;value</I>)</CODE><A NAME="4">&nbsp;</A>
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